Multiple Pilomatricomas: A Retrospective Study and Literature Review

Pilomatricoma is usually a single lesion. However, some patients present with more than one, a fact that has been reported in association with several systemic diseases. The aim of this analysis is to determine the prevalence of multiple pilomatricomas (MP) in our institution as well as to describe their clinical features and associated comorbidities. This is a retrospective analysis reviewing patients with a histological diagnosis of pilomatricoma registered in the database of the Pathology Department of our institution, from January 2005 to March 2017. One hundred ninety-five patients with histological criteria for pilomatricoma were registered. Fourteen (0.7%) of those patients suffered from MP. Among them, the most relevant findings were: 9 (64%) patients were women and 5 (36%) were men. The median age at diagnosis was 16 years. Seven (50%) had 2 pilomatricomas and 7 (50%) had more than 2. Two (14%) suffered from Steinert myotonic dystrophy (SMD). Regarding family background, 3 of them had relatives with pilomatricomas, one of them with pancreatic cancer, and another one with SMD. A total of 36 pilomatricomas were excised from those 14 patients with the following characteristics: The mean lesion size was 12 mm. The majority of the lesions (53%) were located on the head and neck. There was no recurrence or malignant transformation in any patient. Articles reporting on MP are scarce. We communicate 2 new familial MP without associated comorbidities. We would like to highlight that 2 of our patients with MP also developed SMD, an association previously reported. Thus, a thorough physical examination and inquiring about family history are of utmost importance for an early diagnosis of possible associated diseases.